ECN Forum Forums General Topics of the Trade General Discussion Area Receptacles for Stereophiles

Paul,

You just found a new business, the flux lines from the earth's magnetic field are in constant movement, so all you need is a map with the field changes, something like a flight map, and you can schedule for a hefty fee, equipment moves, based on field movement, i notice my audio equipment is off a little since the earths lines moved, or is that my ears aging, due to over exposure to hard rock bands.

That reminds me of a discussion at a German board... NYM cable (equivalent to NM) is round, and when adopting the new color codes they changed the order of the wires from black-brown-blue-ye/gn to something else, I think brown-black-blue-ye/gn looking at the end of the cable. And some guys were seriously discussing whether it would be ILLEGAL to use old cable with the different order!
Adn another guy proceeded to ask: "Why??? Does that confuse the electrons? Do they get dizzy if black and brwon are reversed???"

One thing to keep in mind when 'poo-poo'ing all of the strange audio gear: the human ear is very sensitive to distortion and correlated noise, the human brain is very adaptable and can be trained to either notice or ignore small stimuli, and audio equipment has extremely high gain, and can amplify very small perturbations.

Add to this the fact that people tend to develop mythology when there is something that the cannot understand, that most people don't understand physics very well, and that the engineering is subtle and complex, and you get a situation where there may be _real_ effects, but the theory and marketing is simply full of ignorant hooey. The net result is that you have _real_ effects, which people can notice through hearing, yet without a solid basis in physical understanding, you end up with no good fixes, simply bad marketing.

As NJwirenut noted: if the power supply of an amplifier is so sensitive to external noise that changing the receptacle or supply wiring changes the sound, then there is a design flaw in the power supply. However it would not surprise me in the least that many power supplies _are_ poorly designed by that metric. In the discussion on shared neutrals, someone who works with professional audio equipment describes his _experience_ with problems on shared neutral circuits. These problems go away when the neutral is not shared...IMHO a problem with the power supply design, not with the shared neutral circuits.

It would not surprise me if the 'audiophile' receptacles made some difference in rectification or microphonic effects, which _could_ be measured with the appropriate instruments. The _actual_ effects, if they exist, will certainly be different from those 'predicted' by the mythology, and any 'fixes' at the level of the receptacle would merely be 'work-arounds' for the real problems in the power supply. If the power supply is so sensitive to these changes that such effects can be heard, then something is broken someplace else.

The 'green pen on the CDs' line reminds me of the following:

Just before he died, Gabe Wiener was doing proper research on the 'sound' of CDs. He (among others) found that in well controlled double blind studies, listeners could tell the difference between two CDs of exactly the same music, both of which, when read by a computer, resulted in _exactly_ the same digital data. People could even hear the difference between a source CD and a CDR burned from that source. This is totally at odds with the digital marketing of 'perfect sound forever'. Lots of people heard these effects, and came up with different mythologies, and thus you had 'green pens', little adhesive disks and rings to 'damp' the CDs, very expensive transports with separate DACs, etc.

Rather than coming up with mythology to explain these results, Gabe was part of a group that looked for physically plausible and _measureable_ explanations. I do not remember all of the physically plausible distortion and noise paths that they found, but the list included power supply noise from the laser tracking servos leaking into the analog output stages and clock noise caused by changes in the rate data was read off the CD. Apparently many of the high end external DAC systems didn't bother to generate a high quality internal DAC clock, and simply used the incoming data as the clock source; this would make the external DAC sensitive to _analog_ noise on the CD transport and _digital_ signal lines. The list went on, with many examples of systems which were engineered to _function_, but which did not properly account for subtle but well understood physical principals. These systems were sensitive to noise sources that they _should_ have been immune to.

Did green pens make a difference? Probably not. But the 'damping rings' probably did make a difference, isolating transports from microphonic effects probably did make a difference, and thus there was truth at the core of the mythology.

One could probably have fun _and_ retain some self respect by marketing to this crowd, possibly by making it explicit that you are selling fixes for things that shouldn't be a problem, and then grounding these fixes in solid physics.

-Jon

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Back to Electical. Have you noticed how many restaurants and shops are putting compact florescents in their recessed cans? Pretty Ugly. Probably good savings tho. (california)
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My two cents? I spec'ed this for a friend's shop I designed with his help (he was the carp, but had a HO's license). I needed more light than the cans could provide (since they were IC), so I used PAR38's with CFL sources, lit the place up right nicely. Personally, I wouldn't do it for comm, but it's all in how it looks. (Sorry about the mini-threadjack)